checkArgument(occurrences <= Integer.MAX_VALUE - frequency);
      backingMap.put(element, frequency + occurrences);
      return frequency;
    }

    @Override
    Iterator<E> elementIterator() {
      return Multisets.elementIterator(entryIterator());
    }

    @Override
    Iterator<Entry<E>> entryIterator() {
      final Iterator<Map.Entry<E, Integer>> backingEntries = backingMap.entrySet().iterator();

    }

    @Override
    Set<E> createElementSet() {
      return Sets.filter(unfiltered.elementSet(), predicate);
    }

    @Override
    Iterator<E> elementIterator() {
      throw new AssertionError("should never be called");
    }

    @Override
    Set<Entry<E>> createEntrySet() {
      return Sets.filter(
          unfiltered.entrySet(),

    }

    @Override
    Set<E> createElementSet() {
      return Sets.filter(unfiltered.elementSet(), predicate);
    }

    @Override
    Iterator<E> elementIterator() {
      throw new AssertionError("should never be called");
    }

    @Override
    Set<Entry<E>> createEntrySet() {
      return Sets.filter(
          unfiltered.entrySet(),

      checkArgument(occurrences <= Integer.MAX_VALUE - frequency);
      backingMap.put(element, frequency + occurrences);
      return frequency;
    }

    @Override
    Iterator<E> elementIterator() {
      return Multisets.elementIterator(entryIterator());
    }

    @Override
    Iterator<Entry<E>> entryIterator() {
      final Iterator<Map.Entry<E, Integer>> backingEntries = backingMap.entrySet().iterator();

   * was retrieved.
   */
  @Override
  public Set<Multiset.Entry<E>> entrySet() {
    return super.entrySet();
  }

  @Override
  Iterator<E> elementIterator() {
    final Iterator<Map.Entry<E, Count>> backingEntries = backingMap.entrySet().iterator();
    return new Iterator<E>() {
      @CheckForNull Map.Entry<E, Count> toRemove;

      @Override

      }
    } else {
      node = header.pred();
    }
    return (node == header || !range.contains(node.getElement())) ? null : node;
  }

  @Override
  Iterator<E> elementIterator() {
    return Multisets.elementIterator(entryIterator());
  }

  @Override
  Iterator<Entry<E>> entryIterator() {
    return new Iterator<Entry<E>>() {
      @CheckForNull AvlNode<E> current = firstNode();

      }
    } else {
      node = header.pred();
    }
    return (node == header || !range.contains(node.getElement())) ? null : node;
  }

  @Override
  Iterator<E> elementIterator() {
    return Multisets.elementIterator(entryIterator());
  }

  @Override
  Iterator<Entry<E>> entryIterator() {
    return new Iterator<Entry<E>>() {
      @CheckForNull AvlNode<E> current = firstNode();

      }

      @Override
      public boolean removeAll(Collection<?> c) {
        return standardRemoveAll(c);
      }
    };
  }

  @Override
  Iterator<E> elementIterator() {
    throw new AssertionError("should never be called");
  }

  /** @deprecated Internal method, use {@link #entrySet()}. */
  @Deprecated
  @Override
  public Set<Multiset.Entry<E>> createEntrySet() {

    public void clear() {
      multimap.clear();
    }

    @Override
    public Set<K> elementSet() {
      return multimap.keySet();
    }

    @Override
    Iterator<K> elementIterator() {
      throw new AssertionError("should never be called");
    }
  }

  /** A skeleton implementation of {@link Multimap#entries()}. */